<!DOCTYPE html>
<html lang="en">
	<head>
		<meta charset="UTF-8" />
		<meta http-equiv="X-UA-Compatible" content="IE=edge" />
		<meta name="viewport" content="width=device-width, initial-scale=1.0" />
		<title>Document</title>

		<style>
			.ball {
				width: 100px;
				height: 100px;
				background: #f40;
				border-radius: 50%;
				margin: 30px;
			}

			.ball1 {
				animation: move1 1s alternate infinite ease-in-out;
			}

			.ball2 {
				position: fixed;
				left: 0;
				animation: move2 1s alternate infinite ease-in-out;
			}

			@keyframes move1 {
				to {
					transform: translate(100px);
				}
			}

			@keyframes move2 {
				to {
					left: 100px;
				}
			}
		</style>
	</head>
	<body>
		<button id="btn">死循环</button>
		<div class="ball ball1"></div>
		<div class="ball ball2"></div>
		<script>

			function delay(duration) {
				var start = Date.now();
				while (Date.now() - start < duration) {
					
				}
			}

			btn.onclick = function() {
				delay(5000);
				console.log(666666666);
			};
		</script>
		<div>666666</div>
	</body>
</html>